Measurement Computing Personal Daq/3000 Series - Manual (Page 75)

Pattern Generation Output
Two of the 8-bit ports can be configured for 16-bit pattern generation. The pattern can be updated synchronously
with an acquisition at up to 4 MHz.
Counters
One Counter Channel, Typical
Each of the four high-speed, 32-bit counter channels can be configured for counter, period, pulse width, time
between edges, or multi-axis quadrature encoder modes. Counter inputs can be scanned synchronously along
with analog and digital scanned inputs, based on an internal programmable timer, or an external clock source.
Channels
: 4 x 32-bit
Input Frequency
: 20 MHz maximum
Input Signal Range
: -5V to +10V
Input Characteristics
: 10 kΩ pull-up, 200Ω series resistor, ±15 kV ESD protection
Trigger Level
: TTL
Minimum pulse width
: 25 ns high, 25 ns low
Debounce Times
: 16 selections from 500 ns to 25.5 ms. Positive or negative edge sensitive.
Glitch detect mode or debounce mode.
Time Base Accuracy:
50 ppm (0º to 50ºC)
Five Programmable Modes
: Counter, Period, Pulsewidth, Timing, Encoder
1. Counter Mode Options
: Totalize, Clear on Read, Rollover, Stop at all Fs, 16-bit or 32-bit, any other
channel can gate or decrement the counter
2. Period Mode Options
: Measure x1, x10, x100, or x1000 periods, 16-bit or 32-bit, 4 time bases to
choose from (20.83 ns, 208.3 ns, 2.083 µs, 20.83 µs), any other channel can gate the period measurement
3. Pulsewidth Mode Options
: 16-bit or 32-bit values, 4 time bases to choose from (20.83 ns, 208.3 ns,
2.083 µs, 20.83 µs), any other channel can gate the pulsewidth measurement
4. Timing Mode Options
: 16-bit or 32-bit values, 4 time bases to choose from (20.83 ns, 208.3 ns,
2.083 µs, 20.83 µs)
5. Encoder Mode Options
: x1, x2, x4 options, 16-bit or 32-bit values, Z-channel clearing of the counter,
any other channel can gate the counter
Multi-axis Quadrature Encoder Inputs
:
o
1 channel with A (phase), B (phase), and Z (index)
o
2 channel with A (phase) and B (phase)
o
x1, x2, and x4 count modes
o
Single-ended TTL
Note : Specifications are subject to change without notice. 937492 Specifications 7-9